JP6080942B2 - Dark shade dyeing method for microporous track-etched membranes with large pores and low porosity - Google Patents

Description

Cross-reference of related applications

  This application claims priority to US Provisional Patent Application No. 61 / 619,033, filed Apr. 2, 2012, the entire contents of which are hereby incorporated by reference.

  The present invention relates to a method for dyeing a microporous track-etched membrane, and more particularly to a method for dark shade dyeing a membrane having a pore diameter of 0.8 μm or more.

In general, dyeing methods for microporous polyester track-etched membranes with pores having a diameter of less than 0.8 μm (so-called “small pores”) and high porosity are disclosed in aqueous / alcohol systems. In use, the dye is subsequently fixed and reduced with a sulfite- containing solution, or the residual dye is removed from the membrane surface by washing with a suitable solvent or surfactant. Because of the large number of pores with individually dyed walls, it is possible to achieve a dark shade of color using this technique.

  In contrast, pores with a maximum pore diameter of 0.8 μm or more (so-called “large pores”) and low porosity membranes have relatively few internal pores and walls. Therefore, in order to obtain a dark shade that substantially blocks transmission at one or more wavelengths, it is essential to stain more of the membrane material itself as compared to a membrane with small pores and high porosity. is there. Although the use of disperse dyes in solvent systems with relatively high boiling alcohols or other hydrocarbons may be used to obtain this result, removal of such solvents is difficult and It can adversely affect cell culture, which is a common use of such membranes. Furthermore, typically a relatively high temperature above the glass transition temperature of a membrane material such as polyethylene terephthalate (PET) is used to move the dye molecules across the polymer chain to obtain a substantial dyeing effect.

  However, this approach often results in changes in the structure of the membrane material that can result in changes in membrane parameters such as pore size or surface roughness. Accordingly, there is a need for an improved method for obtaining dark shade dyeing for microporous track-etched membranes having large pores and low porosity.

The present invention provides a method of staining a microporous membrane. Such a method is particularly suitable for dark shade dyeing of membranes having large pores with low porosity. Desirably, these methods, a membrane parameters obtained as a result, significantly have changed product compared to that of before dyeing, an aqueous system. Similarly, the resulting stained membrane does not show any adverse effects on sensitive cell culture system applications.

  In one aspect, the present invention is a method for dyeing a microporous membrane, the membrane being an aqueous disperse dye system and at a temperature of 90-100 ° C. sufficient to provide a desired transmission spectrum for the membrane. The aqueous disperse dye system comprising a dye additive and a dye selected from the group of azo and anthraquinone dyes, and then the membrane at a temperature of 110-150 ° C. A method is provided comprising the step of heating by exposure for 90 minutes.

  In another aspect, the present invention provides a stained membrane prepared according to any of the methods of the present invention.

  In yet another aspect, the present invention provides a cell culture system comprising a membrane stained according to any of the methods of the present invention.

  These and other features of the invention will be better understood upon review of the following detailed description.

  As used herein, the following terms shall have the definitions set forth below.

  As used herein, the phrase “large pores” refers to membranes where the maximum pore size present therein has a diameter of 0.8 μm or greater.

  As used herein, the phrase “low porosity” refers to a membrane that has a relatively small number of pores per unit area of the membrane. In contrast, the phrase “high porosity” refers to a membrane having pores with a relatively high number of pores per unit area of the membrane.

  As used herein, the phrase “substantially blocking transmission” with respect to the membrane means at least a 90% reduction in light transmission at one or more wavelengths, more preferably light at one or more wavelengths. Refers to a reduction of at least 95% in the transmission.

  A method of dyeing a microporous membrane comprising contacting the membrane with an aqueous disperse dye system at a temperature of about 100 ° C. for a period of time sufficient to provide a desired transmission spectrum for the membrane. The disperse dye system is heated by exposing the membrane to a temperature of 110-150 ° C. for 20-90 minutes, comprising a dye additive and a dye selected from the group consisting of an azo dye and an anthraquinone dye. And fixing the dye absorbed on the membrane. Preferably, following heating, the membrane is contacted with a solvent to remove residual dye from the surface of the membrane.

  In one embodiment, the membrane is contacted with the aqueous disperse dye system at a temperature of about 100 ° C. for a period of 20 to 90 minutes.

  In one embodiment, the step of heating the membrane and fixing the dye therein uses a heated film transport cylinder. In particular, fixation results in diffusion of the dye into the polymer matrix.

Residual dye at the surface of the membrane is a sulfite containing agent (eg, REDULIT RED or MEROPAN RED, both available from CHT Bezema (Germany), ERIOPON RC (available from Huntsman, Singapore), or PERIGEN THD available from Dr. Petry (Germany), or non-sulfite- containing solvents that are alkaline (eg, PERISTAL RCV available from Dr. Petry, Germany, or CHT Bezema ( Reduced with REDULIT GIN) available from Germany); then removed by washing with water having a temperature of 40-70 ° C.

In one embodiment, the solvent includes a sulfite- containing agent. In another embodiment, the solvent is alkaline. In one embodiment, the solvent has an alkalinity of pH 11-13. In yet another embodiment, the solvent is selected from ketones, aldehydes, ethers, esters, alcohols, or combinations of two or more thereof. Exemplary suitable solvents include, but are not limited to, ethanol, butanol, ethyl acetate, butyl acetate, acetone, or combinations of two or more thereof.

  In one embodiment, the solvent is an aqueous system.

  The treatment with the solvent is carried out at a temperature of 10-25 ° C., thus preventing the diffusion of the solvent into the polymer.

  In yet another embodiment, the method further comprises washing the surface of the membrane with water, preferably having a temperature of 40-70 ° C., after contacting the membrane with a solvent. Further, in one embodiment, the method further comprises the step of drying the membrane following cleaning of the surface. In one embodiment, air at a temperature of 100-160 ° C. is used to dry the membrane.

  In one embodiment, the method further includes on-line measurement of the transmission spectrum of the membrane.

  Advantageously, the method of drying a microporous membrane described herein is suitable for a continuous roll-to-roll process with final on-line control of the transmission spectrum of the stained membrane.

  Dyes suitable for use in the method of the present invention are disperse dyes selected from the azo and anthraquinone chemical classes. In particular, dyes having relatively small molecules with a molar mass of 700 to 900 g / mol are preferred. Exemplary dyes used in the methods of the present invention include, but are not limited to, Terasil dye family (eg, TERASIL BLACK BFE, TERASIBL BLUE BGE; available from Huntsman, Singapore), Bemachron dye (CHT Bezema, from Germany). And Fantagen dyes (Farbchemie Braun, available from Germany). Preferably, the amount of dye used in the process of the present invention is 4-15% w / v. In certain embodiments, the one or more dyes include those from the Terasil dye family (available from Huntsman, Singapore) in an amount of 4-15% w / v.

  It will be appreciated by those skilled in the art that the dyes can be mixed or blended to obtain the desired transmission spectrum. Alternatively, to obtain the desired transmission spectrum, the membrane can be placed under two or more aqueous dye dispersions with different dyes therein. For example, combinations of dyes such as black, blue, and red or orange dyes may be used to obtain full coverage of the 350-700 nm spectral region in the membrane. In one embodiment, the dye is black, blue, red, orange, or a combination of two or more thereof. In another embodiment, the dyes used are blue and red. In yet another embodiment, the dyes used are blue and orange.

The aqueous disperse dye system includes at least one dye additive. Exemplary dye additives include, but are not limited to, carriers, equilibration agents, diffusion enhancers (eg, UNIVADINE DFM or UNIVADINE DIF, both available from Huntsman, Singapore), dispersants, surfactants, Examples include antifoaming agents and dust control agents. Desirably, at least one dye additive added to the aqueous disperse dye system helps to obtain uniform adsorption of the dye to the membrane surface and / or allows diffusion of dye molecules between the polymer chains of the membrane. Increase. Preferably, the amount of dye additive used in the method of the present invention is 0.5-3 wt / vol%.

  In one embodiment, the dye additive is selected from the group consisting of a carrier, an equilibration agent, a diffusion enhancer, or a combination of two or more thereof. Exemplary staining additives include, but are not limited to, UNIVADINE DFM or UNIVADINE DIF, both available from Huntsman (Singapore), COLORCONTIN, both available from CHT Bezema (Germany), both Dr. PERIGEN CU or PERIGEN CD available from Petry (Germany). In one embodiment, the dye additive is a carrier. In certain embodiments, the carrier is glycerol triacetate. In yet another embodiment, the dye additive is a diffusion enhancer. In certain embodiments, the one or more dye additives comprise a diffusion enhancer available from Huntsman (Singapore) in an amount of 0.5-3 wt / vol%.

  Further, in certain embodiments, the one or more dyes comprises from the Terasil dye family (available from Huntsman, Singapore) in an amount of 4-15 wt / vol%, and the one or more dye additives are , A diffusion promoter available from Huntsman (Singapore) in an amount of 0.5-3 wt / vol%.

  Membranes suitable for use in the present invention include thermoplastic polymers in their composition and are non-fibrous. Exemplary thermoplastic polymers include, but are not limited to, polyethylene terephthalate, poly (vinyl chloride), poly (vinyl) alcohol, and polystyrene. In one embodiment, the membrane comprises polyethylene terephthalate (PET).

  A membrane suitable for use in the present invention has a plurality of pores therein disposed substantially perpendicular to the face of the membrane. Appropriately sized pores can be generated by any known method, such as track etching. In one preferred embodiment, the membrane has a pore size (“large pores”) of 0.8 μm or greater. Such a method is particularly suitable for dark shade dyeing of microporous track-etched membranes having large pores with low porosity, for example for the preparation of dyed membranes having a pore size of 0.8 μm or more. .

  Preferably, the transmission spectrum of a membrane stained according to any of the methods described above is reduced by at least 75%, more preferably by at least 90% compared to the membrane before staining. Such a staining membrane is desirable for use as a fluorescence blocking filter.

  Also provided are stained membranes prepared according to the methods described herein. In one embodiment, such a staining membrane substantially blocks transmission of one or more wavelengths. In another embodiment, such a staining membrane has a pore size of 0.8 μm or more.

  Advantageously, stained membranes prepared according to the methods described herein are suitable for use in cell culture system applications.

  In one embodiment (1), the present disclosure is a method of staining a microporous membrane that provides the membrane with an aqueous disperse dye system and a desired transmission spectrum for the membrane at a temperature of 90-100 ° C. The aqueous disperse dye system comprises a dye additive and a dye selected from the group consisting of an azo dye and an anthraquinone dye, and thereafter the membrane is treated at 110-150 ° C. A method comprising heating by exposure to a temperature of 20 to 90 minutes.

  In certain embodiments (2), the present disclosure provides the invention of embodiment (1), wherein the period is 20 to 90 minutes.

  In certain embodiments (3), the present disclosure provides the invention of embodiment (1), wherein the dye is present at a concentration of 4-15% w / v.

  In certain embodiments (4), the present disclosure provides the invention of embodiment (1), wherein the dye additive is present at a concentration of 0.5-3 wt / vol%.

  In certain embodiments (5), the present disclosure provides embodiments (1) to (4) wherein the dye additive is selected from the group consisting of a carrier, an equilibration agent, a diffusion enhancer, or a combination of two or more thereof. One of the inventions is provided.

  In certain aspect (6), the present disclosure provides the invention of any one of aspects (1) to (5), wherein the dye additive is a carrier.

  In certain embodiment (7), the present disclosure provides the invention of any one of embodiments (1) to (5), wherein the dye additive is a diffusion accelerator.

  In an aspect (8), the present disclosure provides the invention according to any one of aspects (1) to (7), wherein the heating step uses a heated film transport cylinder.

  In certain embodiments (9), the present disclosure further comprises a step of contacting the membrane with a solvent to remove residual dye from the surface of the membrane following the heating step. One invention is provided.

In certain embodiments (10), the present disclosure provides the invention of embodiment (9), wherein the solvent comprises a sulfite- containing agent.

  In certain embodiments (11), the present disclosure provides the invention of embodiment (9), wherein the solvent is alkaline.

  In certain embodiments (12), the present disclosure provides the invention of embodiment (9), wherein the solvent is selected from ketones, aldehydes, ethers, esters, alcohols, or combinations of two or more thereof.

  In certain embodiments (13), the present disclosure provides the invention of embodiment (9), further comprising the step of washing the surface of the membrane with water after contacting the membrane with a solvent.

  In certain embodiments (14), the present disclosure provides the invention of embodiment (13), further comprising the step of drying the membrane following cleaning of the surface thereof.

  In certain embodiments (15), the present disclosure provides the invention of embodiment (1), further comprising on-line measurement of the transmission spectrum of the membrane.

  In certain embodiments (16), the present disclosure provides the invention of embodiment (1), wherein the dye is black, blue, red, orange, or a combination of two or more thereof.

  In certain embodiments (17), the present disclosure provides a stained membrane prepared according to the method described in the invention of embodiment (1).

  In certain embodiments (18), the present disclosure provides the invention of embodiment (17), wherein the staining membrane substantially blocks transmission of one or more wavelengths.

  In an aspect (19), the present disclosure provides the invention of aspect (17), wherein the staining membrane has pores having a diameter of 0.8 μm or more.

  In certain embodiments (20), the present disclosure provides a cell culture system comprising a membrane stained according to the method described in the invention of embodiment (1).

  In certain aspect (21), the present disclosure provides the invention of any one of aspects (1) to (4), wherein the staining additive is a carrier.

  In certain aspect (22), the present disclosure provides the invention of any one of aspects (1) to (4), wherein the dye additive is a diffusion accelerator.

  In certain embodiments (23), the present disclosure provides the invention of embodiment (1), further comprising the step of contacting the membrane with a solvent to remove residual dye from the surface of the membrane following the heating step.

  Aqueous staining solutions include 4-15% w / v TERAIL BLACK BFE, 0.5-5% w / v TERAIL BLUE BGE, 0.5-5% w / v Universadin DIF, and 5-10% w / v. Prepared by mixing volume% acetate buffer pH 4.5. The aqueous dyeing solution was heated to a temperature of 90-100 ° C. The membrane was added to the aqueous staining solution at a temperature of about 100 ° C. and incubated for 20-60 minutes with continuous stirring. Thereafter, the membrane was baked at a temperature of 110 to 150 ° C. for 20 to 90 minutes to absorb and fix the dye therein. At this point, two alternative processes for removing residual dye from the surface of the membrane may be used.

  In one approach, the membrane is contacted with 1-5 wt / vol% REDULIT GIN in an aqueous alkaline solution (pH 11-13) at a temperature of 60-80 ° C. for 15-30 minutes to provide residual dye present therein. Decrease. Thereafter, the membrane is washed with water until it becomes transparent at a temperature of 40-60 ° C., and then dried with air at a temperature of room temperature (about 22 ° C.)-60 ° C. In one embodiment, the membrane is dried with air at a temperature of 40-60 ° C.

  Alternatively, the membrane is contacted with an organic solvent such as ethyl acetate or acetone for about 15 minutes at a temperature of 10-25 ° C., followed by washing with water at a temperature of 90-100 ° C. until clear. Thereafter, the membrane is dried with air at a temperature of room temperature (about 22 ° C.) to 60 ° C. In one embodiment, the membrane is dried with air at a temperature of 40-60 ° C.

Comparison of membrane parameters and performance after the staining process PET track etched membranes were stained and the membrane parameters and their performance were compared to such membranes prior to drying. In particular, two different sized membranes were examined. One membrane has pores having a diameter of 8 μm, a pore density of about 5E + 04 pores / cm ² and a thickness of about 17 μm. The other membrane has pores having a diameter of 3 μm, a pore density of about 6E + 05 pores / cm ² and a thickness of about 20 μm. Both such membranes have the same base film material. Briefly, PET track etched membranes were prepared at 25-40 g / L Terasil Black BFE, 6-10 g / L Terasyl Blue BGE-01, 6-15 g / L Univadine DIF, and 50-100 ml / L pH4. Staining was carried out using a staining solution containing 5 acetate buffer. A small piece of membrane was pushed into the staining solution at 90-100 ° C. for 30-1 hour, during which time the solution was continuously stirred. Thereafter, the stained membrane was air-dried at room temperature. The stained membrane was baked at 130 to 150 ° C. for 30 minutes to 1 hour. Excess dye was removed from the surface of the dry membrane by washing with a solvent such as ethyl acetate, acetone, or alcohol until the surface appeared clear, followed by washing with boiling water. Thereafter, the dried membrane was air dried at room temperature.

In order to measure the membrane thickness, a guidance piece caliper (Mahr, Germany extrax) by positioning a flat piece of membrane on a small flat ceramic plate and tilting the caliper measurement point on the flat membrane. Was used to measure the thickness of the membrane. The thickness was measured at 5 points on the membrane. The intermediate thickness was calculated and recorded with measurement tolerances. For both membranes, the thickness was in the same range before and after staining .

  Furthermore, the track-etched polyethylene terephthalate membrane dyed according to the above method showed no change in its pore size and shape compared to that shown before dyeing. In particular, transparent membranes with pores having a diameter of 7.7 ± 0.4 μm before staining showed the same range of pore sizes after staining (ie, 7.7 ± 0.4 μm). Similarly, membranes with pores having a diameter of 3.2 ± 0.2 μm before staining showed the same pore size after staining.

For the measurement of air flow, an experimental device equipped with a membrane holder, manometer, mass flow meter, and valve was used. Specifically, the measuring instruments used are mass flowmeters (both of the Omega FMAXxx series) having a range of 0-500 ml / min and 0-2000 ml / min, and 0-70 mbar (0-70 hectopascals). ) Manometer (MH28 by Thommen). The membrane disc was placed in a holder with an open membrane area of 6 mm diameter. After closing the holder, the inlet valve was opened. Appropriate air flow was adjusted to obtain measurements in the upper four half of the instrument's measurement range. Air flow and pressure records were taken and standardized air flow data in L / min cm ² bar was calculated and recorded. Three values were obtained for each measurement membrane. Intermediate airflow was calculated and recorded with tolerances. For both membranes, the airflow was in the same range before and after staining .

  Furthermore, no adverse effect was observed on the sensitive cell culture system using the membrane stained according to the above method. In particular, the 56-hour assay was performed using membranes with human umbilical vein endothelial cells and pores having a diameter of 8 μm stained as described above. Desirably, the dyed membrane performed very well and no adverse effects of the dyeing process were observed.

  It will be appreciated by those skilled in the art that changes may be made to the above embodiments without departing from the broad inventive concept. Accordingly, the invention is not limited to the specific embodiments disclosed, but is intended to cover modifications that are within the spirit and scope of the invention as defined by the appended claims. It is understood.

Claims (10)

In a method of staining a microporous membrane,
Contacting the membrane with an aqueous disperse dye system at a temperature of 90-100 ° C. for a period of 20-90 minutes sufficient to provide the desired transmission spectrum for the membrane, the aqueous disperse dye The system comprises a dye additive selected from a carrier, an equilibrator, a diffusion enhancer, a dispersant, a surfactant, an antifoam agent, a dust control agent, or a combination of two or more thereof, and an azo and anthraquinone dye. Comprising: a dye selected from the group; and then heating the membrane by exposing it to a temperature of 110-150 ° C. for 20-90 minutes,
A method comprising the steps of:   The process according to claim 1, characterized in that the dye is present in a concentration of 4 to 15% w / v.   The method according to claim 1, characterized in that the dye additive is present in a concentration of 0.5 to 3% w / v. It characterized in that the dyeing additive is a carrier, the method according to any one of claims 1-3. It characterized in that the dyeing additive is a diffusion accelerator, the method according to any one of claims 1-3. The heating step is characterized by using a heating film conveying cylinder, the method according to any one of claims 1-5. The method according to any one of claims 1 to 6 , further comprising a step of contacting the membrane with a solvent to remove residual dye from the surface of the membrane following the heating step. The method of claim 7 , wherein the solvent comprises a sulfite- containing agent. The method according to claim 7 , wherein the solvent is alkaline. The method of claim 7 , wherein the solvent is selected from ketones, aldehydes, ethers, esters, alcohols, or combinations of two or more thereof.